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对挤压铸造A356铝合金汽车轮毂进行了模拟。根据轮毂不同位置的凝固时间,分析得出了轮毂不同位置的凝固方式,并试验研究了挤压铸造下轮毂不同位置的组织不均匀性。得出轮毂不同位置的组织与凝固方式的关系:急冷区的凝固方式为逐层凝固,晶粒尺寸与组织分布较为均匀;压力结晶区的凝固方式为同时凝固,组织分布均匀,晶粒圆整;急冷区和压力结晶区之间的区域的凝固方式属于糊状凝固,晶粒尺寸与组织分布不均匀,共晶Si大量偏聚在晶界处。
A356 die-cast aluminum alloy car wheels were simulated. According to the setting time of the hub at different positions, the way of solidification at different positions of the hub was analyzed and the microstructure heterogeneity at different positions of the hub under squeeze casting was experimentally studied. The relationship between the microstructure and the solidification mode at different positions of the wheel hub is obtained. The solidification mode of the quench zone is layer-by-layer solidification, and the grain size and the distribution of the microstructure are uniform. The solidification mode of the pressure crystallization zone is simultaneous solidification, . The solidification mode in the region between the quench zone and the pressure crystallization zone belongs to the paste-like solidification. The grain size and the distribution of the microstructure are not uniform. Eutectic Si is segregated at the grain boundaries in a large amount.